Human intestinal organoids from Cronkhite-Canada syndrome patients reveal link between serotonin and proliferation

Cronkhite-Canada Syndrome (CCS) is a rare, noninherited polyposis syndrome affecting 1 in every million individuals. Despite over 50 years of CCS cases, the etiopathogenesis and optimal treatment for CCS remains unknown due to the rarity of the disease and lack of model systems. To better understand the etiology of CCS, we generated human intestinal organoids (HIOs) from intestinal stem cells isolated from 2 patients. We discovered that CCS HIOs are highly proliferative and have increased numbers of enteroendocrine cells producing serotonin (also known as 5-hydroxytryptamine or 5HT). These features were also confirmed in patient tissue biopsies. Recombinant 5HT increased proliferation of non-CCS donor HIOs and inhibition of 5HT production in the CCS HIOs resulted in decreased proliferation, suggesting a link between local epithelial 5HT production and control of epithelial stem cell proliferation. This link was confirmed in genetically engineered HIOs with an increased number of enteroendocrine cells. This work provides a new mechanism to explain the pathogenesis of CCS and illustrates the important contribution of HIO cultures to understanding disease etiology and in the identification of novel therapies. Our work demonstrates the principle of using organoids for personalized medicine and sheds light on how intestinal hormones can play a role in intestinal epithelial proliferation.

[Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction]

OBJECTIVE

To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.

METHODS

A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe²⁺, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.

RESULTS

The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe²⁺ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).

CONCLUSION

SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Live probiotic bacteria administered in a pathomimetic Leaky Gut Chip ameliorate impaired epithelial barrier and mucosal inflammation

Here, we report a pathomimetic Leaky Gut Chip that recapitulates increased epithelial permeability and intestinal inflammation to assess probiotic intervention as live biotherapeutics. We leveraged a mechanodynamic human gut-on-a-chip (Gut Chip) that recreates three-dimensional epithelial layers in a controlled oxygen gradient and biomechanical cues, where the addition of a cocktail of pro-inflammatory cytokines, TNF-α and IL-1β, reproducibly induced impaired epithelial barrier followed by intestinal inflammation. This inflamed leaky epithelium was not recovered for up to 3 days, although the cytokine treatment ceased. However, when probiotic bacteria, either Lactobacillus rhamnosus GG or a multi-species mixture (VSL#3), were respectively administered on the leaky epithelium, bacterial cells colonized mucosal surface and significantly improved barrier function, enhanced the localization of tight junction proteins such as ZO-1 and occludin, and elevated mucus production. In addition, inflammatory markers, including p65, pSTAT3, and MYD88, that were highly expressed in the germ-free control were significantly reduced when probiotic bacteria were co-cultured in a Leaky Gut Chip. Probiotic treatment also significantly reduced the production of secretory pro-inflammatory cytokines. Hence, our pathomimetic Leaky Gut Chip may offer a translational strategy to dissect the therapeutic mechanism of live biotherapeutic products and validate their clinical potential by incorporating patient-derived organoids.

Abstract 3862: Microbial immunomodulation for enhancing immunotherapeutic efficacy in a patient-specific colorectal cancer chip

Immune checkpoint inhibitors (ICI) targeting PD-1, PD-L1, or CTLA-4 have shown remarkable therapeutic outcomes in various cancers. However, the therapeutic efficacy of ICI-based immunotherapy in microsatellite stable (MSS) colorectal cancer (CRC) has been extremely limited. Recent studies strikingly revealed that the human gut microbiome controls the efficacy of immune checkpoint blockades. Yet, the effect of the gut microbiome on reinforcing the ICI efficacy in MSS tumors in CRC is unknown. Here, we suggest a microengineered CRC Chip that recapitulates the tumor microenvironment of individual CRC patients by introducing biopsy-derived colonic organoid epithelium. We have built a three-dimensional (3D) lumen-capillary interface under peristalsis-like motions and flow in an oxygen-controlled microenvironment. We leverage this pathomimetic CRC Chip to recapitulate the patient-specific tumor-microbiome-immune axis to demonstrate microbial immunomodulation on the tumor cells and cytotoxic tumor immunity. We co-cultured various human intestinal bacteria in a CRC Chip to assess the immunomodulatory contribution to the tumor epithelium. We found that living Bifidobacterium sp. significantly reduces the PD-L1 on the tumor surface, followed by elevated anti-tumor activity after CD8 T cell-mediated cytotoxic interactions. We envision that our CRC Chip model can potentially reduce the knowledge gap between the bench and bedside. Furthermore, our innovative CRC Chip model may potentially offer a platform to validate the “Druggable microbiome” and the utility of the patient’s avatar model for Precision Medicine.

Citation Format: Yong Cheol Shin, Alexander Wu, Soyoun Min, Daesung Kim, Woojung Shin, S. Gail Eckhardt, R. Y. Declan Fleming, Hyun Jung Kim. Microbial immunomodulation for enhancing immunotherapeutic efficacy in a patient-specific colorectal cancer chip [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3862.

A Bioprinted Tubular Intestine Model Using a Colon-Specific Extracellular Matrix Bioink

Tremendous advances have been made toward accurate recapitulation of the human intestinal system in vitro to understand its developmental process, and disease progression. However, current in vitro models are often confined to 2D or 2.5D microarchitectures, which is difficult to mimic the systemic level of complexity of the native tissue. To overcome this problem, physiologically relevant intestinal models are developed with a 3D hollow tubular structure using 3D bioprinting strategy. A tissue-specific biomaterial, colon-derived decellularized extracellular matrix (Colon dECM) is developed and it provides significant maturation-guiding potential to human intestinal cells. To fabricate a perfusable tubular model, a simultaneous printing process of multiple materials through concentrically assembled nozzles is developed and a light-activated Colon dECM bioink is employed by supplementing with ruthenium/sodium persulfate as a photoinitiator. The bioprinted intestinal tissue models show spontaneous 3D morphogenesis of the human intestinal epithelium without any external stimuli. In consequence, the printed cells form multicellular aggregates and cysts and then differentiate into several types of enterocytes, building junctional networks. This system can serve as a platform to evaluate the effects of potential drug-induced toxicity on the human intestinal tissue and create a coculture model with commensal microbes and immune cells for future therapeutics.

[The Response and Challenge of New Psychoactive Substances]

Abstract.

The characteristics and risk factors of the postoperative nausea and vomiting in female patients undergoing laparoscopic sleeve gastrectomy and laparoscopic gynecological surgeries: a propensity score matching analysis

OBJECTIVE

The aim of this study was to compare the prevalence of postoperative nausea and vomiting (PONV) in matched patients undergoing laparoscopic sleeve gastrectomy (LSG) and laparoscopic gynecological surgeries (LGS) and investigate the main cause of the high occurrence of PONV in bariatric surgeries.

PATIENTS AND METHODS

Medical records of female patients with a body mass index (BMI) greater than 30 kg/m2 undergoing LSG or LGS from January 1, 2016 to September 1, 2020 were reviewed for PONV episodes in the first postoperative 48 hours. A 1:1 propensity score matching (PSM) method was performed between cases subject to the two types of surgery, and PONV rates were compared.

RESULTS

A total of 278 patients met the inclusion criteria (LSG = 101, LGS = 177), and 74 matched subjects were selected from each group after PSM. An increased occurrence of PONV was noted in female patients with LSG compared with those undergoing LGS (66.2% vs. 23.0%; p<0.001). PONV severity was significantly worse in the LSG (p<0.001), and more frequent use of rescue antiemetics was detected in the LSG group compared with the LGS group (51.4% vs. 17.6%; p<0.001). The time of the first use of rescue drugs was much earlier in the LGS group (p = 0.034).

CONCLUSIONS

Female patients undergoing LSG are at increased risk of PONV compared with those with LGS, indicating a critical role of procedure-related alterations of gastric physiology in the high occurrence of PONV after bariatric surgery.

[Correlation of serum ADAMTS13 and TSP1 levels with myocardial injury and prognosis in patients with acute coronary syndrome]

OBJECTIVE

To investigate serum levels of von Willebrand factor lytic protease (ADAMTS13) and thrombospondin-1 (TSP1) in patients with different types of acute coronary syndrome (ACS) and their correlation with the patients' clinical prognosis.

OBJECTIVE

According to their disease history, results of angiography and clinical biochemical tests, a total of 405 patients undergoing coronary angiography, were divided into unstable angina (UAP) group (n=215), acute myocardial infarction (AMI) group (n=96), and angiographically normal group (n=94). Serum ADAMTS13 and TSP1 levels were detected in all the patients, who were followed up for 15 months to evaluate the occurrence of long-term major cardiac adverse events (MACE).

OBJECTIVE

Serum ADAMTS13 level was significantly lower and TSP1 level was significantly higher in AMI group and UAP group than in the normal group (P < 0.001). Serum ADAMTS13 and TSP1 levels were negative correlated in ACS patients (R=-0.577, P < 0.001). The patients experiencing MACE had significantly different serum TSP1 level from those without MACE (P < 0.05). Cox proportion regression model analysis showed that TSP1 was a risk factor affecting the occurrence of MACE in ACS patients; Kaplan-Meier survival analysis showed that the patients with high levels of TSP1 had a higher incidence of longterm MACE than those with low TSP1 levels.

OBJECTIVE

A lowered serum ADAMTS13 level and an elevated TSP1 level can support the diagnosis of ACS. An elevated TSP1 level may serve as an indicator for predicting the risk of MACE in patients with ACS.

A Global Vista of the Epigenomic State of the Mouse Submandibular Gland

The parotid, submandibular, and sublingual glands represent a trio of oral secretory glands whose primary function is to produce saliva, facilitate digestion of food, provide protection against microbes, and maintain oral health. While recent studies have begun to shed light on the global gene expression patterns and profiles of salivary glands, particularly those of mice, relatively little is known about the location and identity of transcriptional control elements. Here we have established the epigenomic landscape of the mouse submandibular salivary gland (SMG) by performing chromatin immunoprecipitation sequencing experiments for 4 key histone marks. Our analysis of the comprehensive SMG data sets and comparisons with those from other adult organs have identified critical enhancers and super-enhancers of the mouse SMG. By further integrating these findings with complementary RNA-sequencing based gene expression data, we have unearthed a number of molecular regulators such as members of the Fox family of transcription factors that are enriched and likely to be functionally relevant for SMG biology. Overall, our studies provide a powerful atlas of cis-regulatory elements that can be leveraged for better understanding the transcriptional control mechanisms of the mouse SMG, discovery of novel genetic switches, and modulating tissue-specific gene expression in a targeted fashion.

Robust Formation of an Epithelial Layer of Human Intestinal Organoids in a Polydimethylsiloxane-Based Gut-on-a-Chip Microdevice

Polydimethylsiloxane (PDMS) is a silicone polymer that has been predominantly used in a human organ-on-a-chip microphysiological system. The hydrophobic surface of a microfluidic channel made of PDMS often results in poor adhesion of the extracellular matrix (ECM) as well as cell attachment. The surface modification by plasma or UV/ozone treatment in a PDMS-based device produces a hydrophilic surface that allows robust ECM coating and the reproducible attachment of human intestinal immortalized cell lines. However, these surface-activating methods have not been successful in forming a monolayer of the biopsy-derived primary organoid epithelium. Several existing protocols to grow human intestinal organoid cells in a PDMS microchannel are not always reproducibly operative due to the limited information. Here, we report an optimized methodology that enables robust and reproducible attachment of the intestinal organoid epithelium in a PDMS-based gut-on-a-chip. Among several reported protocols, we optimized a method by performing polyethyleneimine-based surface functionalization followed by the glutaraldehyde cross linking to activate the PDMS surface. Moreover, we discovered that the post-functionalization step contributes to provide uniform ECM deposition that allows to produce a robust attachment of the dissociated intestinal organoid epithelium in a PDMS-based microdevice. We envision that our optimized protocol may disseminate an enabling methodology to advance the integration of human organotypic cultures in a human organ-on-a-chip for patient-specific disease modeling.

Spatiotemporal Gradient and Instability of Wnt Induce Heterogeneous Growth and Differentiation of Human Intestinal Organoids

In a conventional culture of three-dimensional human intestinal organoids, extracellular matrix hydrogel has been used to provide a physical space for the growth and morphogenesis of organoids in the presence of exogenous morphogens such as Wnt3a. We found that organoids embedded in a dome-shaped hydrogel show significant size heterogeneity in different locations inside the hydrogel. Computational simulations revealed that the instability and diffusion limitation of Wnt3a constitutively generate a concentration gradient inside the hydrogel. The location-dependent heterogeneity of organoids in a hydrogel dome substantially perturbed the transcriptome profile associated with epithelial functions, cytodifferentiation including mucin 2 expression, and morphological characteristics. This heterogeneous phenotype was significantly mitigated when the Wnt3a was frequently replenished in the culture medium. Our finding suggests that the morphological, transcriptional, translational, and functional heterogeneity in conventional organoid cultures may lead to a false interpretation of the experimental results in organoid-based studies.

Three-Dimensional Regeneration of Patient-Derived Intestinal Organoid Epithelium in a Physiodynamic Mucosal Interface-on-a-Chip

The regeneration of the mucosal interface of the human intestine is critical in the host-gut microbiome crosstalk associated with gastrointestinal diseases. The biopsy-derived intestinal organoids provide genetic information of patients with physiological cytodifferentiation. However, the enclosed lumen and static culture condition substantially limit the utility of patient-derived organoids for microbiome-associated disease modeling. Here, we report a patient-specific three-dimensional (3D) physiodynamic mucosal interface-on-a-chip (PMI Chip) that provides a microphysiological intestinal milieu under defined biomechanics. The real-time imaging and computational simulation of the PMI Chip verified the recapitulation of non-linear luminal and microvascular flow that simulates the hydrodynamics in a living human gut. The multiaxial deformations in a convoluted microchannel not only induced dynamic cell strains but also enhanced particle mixing in the lumen microchannel. Under this physiodynamic condition, an organoid-derived epithelium obtained from the patients diagnosed with Crohn's disease, ulcerative colitis, or colorectal cancer independently formed 3D epithelial layers with disease-specific differentiations. Moreover, co-culture with the human fecal microbiome in an anoxic-oxic interface resulted in the formation of stochastic microcolonies without a loss of epithelial barrier function. We envision that the patient-specific PMI Chip that conveys genetic, epigenetic, and environmental factors of individual patients will potentially demonstrate the pathophysiological dynamics and complex host-microbiome crosstalk to target a patient-specific disease modeling.

Recapitulation of the accessible interface of biopsy-derived canine intestinal organoids to study epithelial-luminal interactions

Recent advances in canine intestinal organoids have expanded the option for building a better in vitro model to investigate translational science of intestinal physiology and pathology between humans and animals. However, the three-dimensional geometry and the enclosed lumen of canine intestinal organoids considerably hinder the access to the apical side of epithelium for investigating the nutrient and drug absorption, host-microbiome crosstalk, and pharmaceutical toxicity testing. Thus, the creation of a polarized epithelial interface accessible from apical or basolateral side is critical. Here, we demonstrated the generation of an intestinal epithelial monolayer using canine biopsy-derived colonic organoids (colonoids). We optimized the culture condition to form an intact monolayer of the canine colonic epithelium on a nanoporous membrane insert using the canine colonoids over 14 days. Transmission and scanning electron microscopy revealed a physiological brush border interface covered by the microvilli with glycocalyx, as well as the presence of mucin granules, tight junctions, and desmosomes. The population of stem cells as well as differentiated lineage-dependent epithelial cells were verified by immunofluorescence staining and RNA in situ hybridization. The polarized expression of P-glycoprotein efflux pump was confirmed at the apical membrane. Also, the epithelial monolayer formed tight- and adherence-junctional barrier within 4 days, where the transepithelial electrical resistance and apparent permeability were inversely correlated. Hence, we verified the stable creation, maintenance, differentiation, and physiological function of a canine intestinal epithelial barrier, which can be useful for pharmaceutical and biomedical researches.

Microphysiological Engineering of Immune Responses in Intestinal Inflammation

The epithelial barrier in the gastrointestinal (GI) tract is a protective interface that endures constant exposure to the external environment while maintaining its close contact with the local immune system. Growing evidence has suggested that the intercellular crosstalk in the GI tract contributes to maintaining the homeostasis in coordination with the intestinal microbiome as well as the tissue-specific local immune elements. Thus, it is critical to map the complex crosstalks in the intestinal epithelial-microbiome-immune (EMI) axis to identify a pathological trigger in the development of intestinal inflammation, including inflammatory bowel disease. However, deciphering a specific contributor to the onset of pathophysiological cascades has been considerably hindered by the challenges in current in vivo and in vitro models. Here, we introduce various microphysiological engineering models of human immune responses in the EMI axis under the healthy conditions and gut inflammation. As a prospective model, we highlight how the human “gut inflammation-on-a-chip” can reconstitute the pathophysiological immune responses and contribute to understanding the independent role of inflammatory factors in the EMI axis on the initiation of immune responses under barrier dysfunction. We envision that the microengineered immune models can be useful to build a customizable patient's chip for the advance in precision medicine.

Transcriptomic and Single-Cell Analysis of the Murine Parotid Gland

The salivary complex of mammals consists of 3 major pairs of glands: the parotid, submandibular, and sublingual glands. While the 3 glands share similar functional properties, such as saliva secretion, their differences are largely based on the types of secretions they produce. While recent studies have begun to shed light on the underlying molecular differences among the glands, few have examined the global transcriptional repertoire over various stages of gland maturation. To better elucidate the molecular nature of the parotid gland, we have performed RNA sequencing to generate comprehensive and global gene expression profiles of this gland at different stages of maturation. Our transcriptomic characterization and hierarchical clustering analysis with adult organ RNA sequencing data sets has identified a number of molecular players and pathways that are relevant for parotid gland biology. Moreover, our detailed analysis has revealed a unique parotid gland-specific gene signature that may represent important players that could impart parotid gland-specific biological properties. To complement our transcriptomic studies, we have performed single-cell RNA sequencing to map the transcriptomes of parotid epithelial cells. Interrogation of the single-cell transcriptomes revealed the degree of molecular and cellular heterogeneity of the various epithelial cell types within the parotid gland. Moreover, we uncovered a mixed-lineage population of cells that may reflect molecular priming of differentiation potentials. Overall our comprehensive studies provide a powerful tool for the discovery of novel molecular players important in parotid gland biology.

Atrophic acne scar: a process from altered metabolism of elastic fibres and collagen fibres based on transforming growth factor-β1 signalling

BACKGROUND

Atrophic acne scar, a persistent sequela from acne, is undesirably troubling to many patients due to its cosmetic and psychosocial aspects. Although there have been some reports emphasizing the role of early inflammatory responses in atrophic acne scarring, evolving perspectives on the detailed pathogenic processes are promptly needed.

OBJECTIVES

Examining the histological, immunological and molecular changes in early acne lesions susceptible to atrophic scarring can provide new insights to understand the pathophysiology of atrophic acne scar.

METHODS

We experimentally validated several early fundamental hallmarks accounting for the transition of early acne lesions to atrophic scars by comparing molecular profiles of skin and acne lesions between patients who were prone to scar (APS) or not (ANS).

RESULTS

In APS, compared with ANS, devastating degradation of elastic fibres and collagen fibres occurred in the dermis, followed by their incomplete recovery. Abnormally excessive inflammation mediated by innate immunity with T helper 17 and T helper 1 cells was observed. Epidermal proliferation was significantly diminished. Transforming growth factor (TGF)-β1 was drastically elevated in APS, suggesting that aberrant TGF-β1 signalling is an underlying modulator of all of these pathological processes.

CONCLUSIONS

These results may provide a basis for understanding the pathogenesis of atrophic acne scarring. Reduction of excessive inflammation and TGF-β1 signalling in early acne lesions is expected to facilitate the protection of normal extracellular matrix metabolism and ultimately the prevention of atrophic scar formation. What's already known about this topic? The dermis of atrophic acne scars shows alteration of extracellular matrix components such as collagen fibres. Inflammation in acne lesions is associated with the development of acne scars. What does this study add? Abnormalities in the metabolism of collagen fibres and elastic fibres were observed in the early developmental stages of acne lesions that were progressing into atrophic scars. Exacerbated inflammation and aberrant epidermal proliferation by increased transforming growth factor (TGF)-β1 signalling may affect the abnormal extracellular matrix metabolism. What is the translational message? Abnormal changes in elastic fibres and collagen fibres are found in the early developmental process of acne in patients who are prone to atrophic scarring. An early treatment regimen strongly inhibiting inflammation and TGF-β1 signalling to help the normal recovery of the extracellular matrix components is required to prevent atrophic scarring.

The expression of transforming growth factor-β1 in myocardial tissue and concentration of serum B-type natriuretic peptide in myocardial remodeling of Sprague-Dawley rats treated with carvedilol

OBJECTIVE

The objective of this study was to observe the expression of transforming growth factor-β1 (TGF-β1) in myocardial tissue and the concentration of serum B-type natriuretic peptide (BNP) in myocardial remodeling of Sprague-Dawley rats induced by isoproterenol (ISO) and the effects of carvedilol intervention.

MATERIALS AND METHODS

Thirty rats were divided randomly into three groups: (1) Control group: rats were injected with 5 mL/(kg·d) of saline for 10 days, followed by 10 mL/(kg·d) of saline by gavage for 4 weeks. (2) Model group: rats were injected with 5 mg/(kg·d) ISO for 10 days, followed by 10 mL/(kg·d) of saline by gavage for 4 weeks. (3) Treatment group: rats were injected with 5 mg/(kg·d) ISO for 10 days, followed by 10 mg/(kg·d) carvedilol by gavage for 4 weeks. Following treatments, the Cardiac Weight Index (CWI) was measured. The pathological changes to myocardial tissue were observed by HE staining and Masson's trichrome staining. The mRNA expression of TGF-β1 was determined by RT-PCR. The protein expression of TGF-β1 was detected by immunohistochemistry and Western blot. The concentration of serum BNP was measured by ELISA.

RESULTS

According to our results, no significant pathological changes were observed in myocardial tissue of the control group. The denaturation, hypertrophy, edema and necrosis of myocardial cells as well as increased collagen fibers in myocardial tissue of the model group, were more pronounced compared to the treatment group. The CWI, level of TGF-β1 in myocardial tissue, and the concentration of serum BNP of the model group, were significantly higher than that of the treatment group, and those of the treatment group were significantly higher than in the control group. There were significant differences among the three groups. There were also significant differences between any two groups.

CONCLUSIONS

The expression of TGF-β1 in myocardial tissue was upregulated and the concentration of serum BNP was increased in myocardial remodeling of SD rats induced by ISO. Carvedilol intervention can downregulate the expression of TGF-β1 and decrease the concentration of BNP, inhibiting myocardial remodeling, and improve cardiac function.

Heightened cleavage of Axl receptor tyrosine kinase by ADAM metalloproteases may contribute to disease pathogenesis in SLE

Systemic lupus erythematosus (SLE) is characterized by antibody-mediated chronic inflammation in the kidney, lung, skin, and other organs to cause inflammation and damage. Several inflammatory pathways are dysregulated in SLE, and understanding these pathways may improve diagnosis and treatment. In one such pathway, Axl tyrosine kinase receptor responds to Gas6 ligand to block inflammation in leukocytes. A soluble form of the Axl receptor ectodomain (sAxl) is elevated in serum from patients with SLE and lupus-prone mice. We hypothesized that sAxl in SLE serum originates from the surface of leukocytes and that the loss of leukocyte Axl contributes to the disease. We determined that macrophages and B cells are a source of sAxl in SLE and in lupus-prone mice. Shedding of the Axl ectodomain from the leukocytes of lupus-prone mice is mediated by the matrix metalloproteases ADAM10 and TACE (ADAM17). Loss of Axl from lupus-prone macrophages renders them unresponsive to Gas6-induced anti-inflammatory signaling in vitro. This phenotype is rescued by combined ADAM10/TACE inhibition. Mice with Axl-deficient macrophages develop worse disease than controls when challenged with anti-glomerular basement membrane (anti-GBM) sera in an induced model of nephritis. ADAM10 and TACE also mediate human SLE PBMC Axl cleavage. Collectively, these studies indicate that increased metalloprotease-mediated cleavage of leukocyte Axl may contribute to end organ disease in lupus. They further suggest dual ADAM10/TACE inhibition as a potential therapeutic modality in SLE.

Epidemiology and risk factors of childhood acne in Korea: a cross-sectional community based study

BACKGROUND

The epidemiology of acne vulgaris appears to be evolving, with an increasingly earlier onset seen in childhood. Relevant studies have been rarely performed in Asia.

AIM

We sought to estimate the prevalence and clinical characteristics of acne among schoolchildren, and its association with treatment-seeking behaviour, body mass index (BMI), nutritional habits and other lifestyle elements.

METHODS

A cross-sectional study was conducted with elementary schoolchildren aged 7-12 years. Children were interviewed by self-administered questionnaires, and were subsequently evaluated by dermatologists.

RESULTS

Of 693 children enrolled, 36.2% were diagnosed with acne, and the prevalence increased with age. Additionally, clinical characteristics including severity, duration of disease and lesion distribution were significantly different between the lower (aged 7-9 years) and the higher (aged 10-12 years) grades. Subjective features including recognition about acne and treatment-seeking behaviours were also different between the two groups. Overweight or obesity (BMI ≥ 25 kg/m(2) at 18 years of age; OR = 2.7) and consumption of chocolates/sweets (OR = 1.6) were significant risk factors for acne.

CONCLUSIONS

In the current study, the prevalence of acne among elementary schoolchildren was high, but only a few children had received treatment. Physicians should be attentive to childhood acne, and educate patients and their parents about the need to treat it.

BANK1 transgenic mice exhibit lupus-associated B cell phenotypes (BA3P.105)

BANK1 is a B-cell adaptor protein that has been implicated in SLE and systemic sclerosis. Previous studies have interpreted that the overexpression of the full length BANK1 isoform plays a pathogenic and the truncated (∆BANK1) version plays a protective role in lupus. However, there is no mechanistic evidence showing that these 2 isoforms can impact lupus development differentially. We have recently generated 2 transgenic strains on the B6 background, BANK1Tg and ∆BANK1Tg, which will be used to address this knowledge gap. The BANK1Tg mice overexpressing the full length Bank1 under the control of CD19 promoter exhibited a dramatic skewing in the splenic B cell population to MZ and B1a cells with a reduction in FO B cells. These mice also exhibited increased plasma cells along with an increased level of total IgM and anti-dsDNA IgG antibodies. Microarray analysis revealed increased transcript levels of several class switched IgG antibodies with a concomitant increase in the level of activation induced deaminase (AID), a master regulator of class switch recombination (CSR). qPCR confirmed higher level of AID and CSR. Interestingly, these phenotypes are observed only in female Tg mice. In contrast, the ∆BANK1Tg mice don’t exhibit the above phenotypes, supporting the hypothesis that the truncated isoform may play a protective role. These studies indicate that the different isoforms of BANK1 observed in humans contribute differentially to the development of B-cell autoimmunity.

Accuracy of Electronic Surveillance of Catheter-Associated Urinary Tract Infection at an Academic Medical Center

Objective.

To develop and validate a methodology for electronic surveillance of catheter-associated urinary tract infections (CAUTIs).

Design.

Diagnostic accuracy study.

Setting.

A 425-bed university hospital.

Subjects.

A total of 1,695 unique inpatient encounters from November 2009 through November 2010 with a high clinical suspicion of CAUTI.

Methods.

An algorithm was developed to identify incident CAUTIs from electronic health records (EHRs) on the basis of the Centers for Disease Control and Prevention (CDC) surveillance definition. CAUTIs identified by electronic surveillance were compared with the reference standard of manual surveillance by infection preventionists. To determine diagnostic accuracy, we created 2 × 2 tables, one unadjusted and one adjusted for misclassification using chart review and case adjudication. Unadjusted and adjusted test statistics (percent agreement, sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV], and κ) were calculated.

Results.

Electronic surveillance identified 64 CAUTIs compared with manual surveillance, which identified 19 CAUTIs for 97% agreement, 79% sensitivity, 97% sensitivity, 23% PPV, 100% NPV, and κ of .33. Compared with the reference standard adjusted for misclassification, which identified 55 CAUTIs, electronic surveillance had 98% agreement, 80% sensitivity, 99% specificity, 69% PPV, 99% NPV, and κ of .71.

Conclusion.

The electronic surveillance methodology had a high NPV and a low PPV compared with the reference standard, indicating a role of the electronic algorithm in screening data sets to exclude cases. However, the PPV markedly improved compared with the reference standard adjusted for misclassification, suggesting a future role in surveillance with improvements in EHRs.

Infect Control Hosp Epidemiol2014;35(6):685–691

Dolutegravir: clinical and laboratory safety in integrase inhibitor-naive patients

BACKGROUND

The efficacy of dolutegravir (DTG) has been demonstrated in 5 randomized studies in integrase inhibitor (INI)-naive adult populations. To date, a detailed safety review of DTG has not been provided in the literature.

OBJECTIVE

To describe the safety and tolerability profile of DTG in adults based on 5 randomized, controlled trials and comparison with drugs in 3 major antiretroviral (ARV) classes.

METHODS

Safety data from phase IIb/III/IIIb trials in ART-naive and ART-experienced, INI-naive adults were integrated.

RESULTS

In 4 ART-naive (SPRING-1, SPRING-2, SINGLE, FLAMINGO) and 1 ART-experienced, INI-naive study (SAILING), 1,579 individuals received a DTG-containing regimen. The proportion of individuals from DTG treatment arms who withdrew due to adverse events (AEs) was low (≤2%) compared to raltegravir (RAL; 2% SPRING-2, 4% SAILING), efavirenz (EFV)-containing comparator arm (10% SINGLE), and darunavir + ritonavir (DRV/r; 4% FLAMINGO). The most frequently observed AEs (diarrhea, nausea, headache), typically grade 1 or 2 in severity, did not lead to study discontinuation. Psychiatric and nervous system disorders with DTG were comparable to RAL- and DRV/r-containing regimens and favorable to EFV-containing regimens. In hepatitis B and/or C coinfected ART-naive individuals, the incidence of transaminase elevations was lower with DTG versus RAL and EFV comparators, but was similar to DRV/r. In SAILING, transaminase elevations were more commonly observed with DTG, particularly in the setting of inadequate hepatitis B therapy or immune reconstitution. On DTG treatment, mild creatinine elevations occurred and stabilized early. Few cases of hypersensitivity reaction and/or severe rash were seen. Rates of these events were comparable to or lower than with RAL-, EFV-, and DRV/r-containing regimens.

CONCLUSIONS

The safety profile for DTG 50 mg once daily in INI-naive individuals was comparable to RAL- and DRV/r-containing regimens and generally favorable compared with EFV-containing regimens.

Accuracy of electronic surveillance of catheter-associated urinary tract infection at an academic medical center

OBJECTIVE

To develop and validate a methodology for electronic surveillance of catheter-associated urinary tract infections (CAUTIs).

DESIGN

Diagnostic accuracy study.

SETTING

A 425-bed university hospital.

SUBJECTS

A total of 1,695 unique inpatient encounters from November 2009 through November 2010 with a high clinical suspicion of CAUTI.

METHODS

An algorithm was developed to identify incident CAUTIs from electronic health records (EHRs) on the basis of the Centers for Disease Control and Prevention (CDC) surveillance definition. CAUTIs identified by electronic surveillance were compared with the reference standard of manual surveillance by infection preventionists. To determine diagnostic accuracy, we created 2 × 2 tables, one unadjusted and one adjusted for misclassification using chart review and case adjudication. Unadjusted and adjusted test statistics (percent agreement, sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV], and κ) were calculated.

RESULTS

Electronic surveillance identified 64 CAUTIs compared with manual surveillance, which identified 19 CAUTIs for 97% agreement, 79% sensitivity, 97% sensitivity, 23% PPV, 100% NPV, and κ of .33. Compared with the reference standard adjusted for misclassification, which identified 55 CAUTIs, electronic surveillance had 98% agreement, 80% sensitivity, 99% specificity, 69% PPV, 99% NPV, and κ of .71.

CONCLUSION

The electronic surveillance methodology had a high NPV and a low PPV compared with the reference standard, indicating a role of the electronic algorithm in screening data sets to exclude cases. However, the PPV markedly improved compared with the reference standard adjusted for misclassification, suggesting a future role in surveillance with improvements in EHRs.

Glutathione S-transferase Mu 2-transduced mesenchymal stem cells ameliorated anti-glomerular basement membrane antibody-induced glomerulonephritis by inhibiting oxidation and inflammation

INTRODUCTION

Oxidative stress is implicated in tissue inflammation, and plays an important role in the pathogenesis of immune-mediated nephritis. Using the anti-glomerular basement membrane antibody-induced glomerulonephritis (anti-GBM-GN) mouse model, we found that increased expression of glutathione S-transferase Mu 2 (GSTM2) was related to reduced renal damage caused by anti-GBM antibodies. Furthermore, mesenchymal stem cell (MSC)-based therapy has shed light on the treatment of immune-mediated kidney diseases. The aim of this study was to investigate if MSCs could be utilized as vehicles to deliver the GSTM2 gene product into the kidney and to evaluate its potential therapeutic effect on anti-GBM-GN.

METHODS

The human GSTM2 gene (hGSTM2) was transduced into mouse bone marrow-derived MSCs via a lentivirus vector to create a stable cell line (hGSTM2-MSC). The cultured hGSTM2-MSCs were treated with 0.5 mM H2O2, and apoptotic cells were measured by terminal dUTP nick-end labeling (TUNEL) assay. The 129/svj mice, which were challenged with anti-GBM antibodies, were injected with 10⁶ hGSTM2-MSCs via the tail vein. Expression of hGSTM2 and inflammatory cytokines in the kidney was assayed by quantitative PCR and western blotting. Renal function of mice was evaluated by monitoring proteinuria and levels of blood urea nitrogen (BUN), and renal pathological changes were analyzed by histochemistry. Immunohistochemical analysis was performed to measure inflammatory cell infiltration and renal cell apoptosis.

RESULTS

MSCs transduced with hGSTM2 exhibited similar growth and differentiation properties to MSCs. hGSTM2-MSCs persistently expressed hGSTM2 and resisted H2O2-induced apoptosis. Upon injection into 129/svj mice, hGSTM2-MSCs migrated to the kidney and expressed hGSTM2. The anti-GBM-GN mice treated with hGSTM2-MSCs exhibited reduced proteinuria and BUN (58% and 59% reduction, respectively) and ameliorated renal pathological damage, compared with control mice. Mice injected with hGSTM2-MSCs showed alleviated renal inflammatory cell infiltration and reduced expression of chemokine (C-C motif) ligand 2 (CCL2), interleukin (IL)-1β and IL-6 (53%, 46% and 52% reduction, respectively), compared with controls. Moreover, hGSTM2-MSCs increased expression of renal superoxide dismutase and catalase, which may associate with detoxifying reactive oxygen species to prevent oxidative renal damage.

CONCLUSIONS

Our data suggest that the enhanced protective effect of GSTM2-transduced MSCs against anti-GBM-GN might be associated with inhibition of oxidative stress-induced renal cell apoptosis and inflammation, through over-expression of hGSTM2 in mouse kidneys.

Pharmacokinetics, safety, and monotherapy antiviral activity of GSK1265744, an HIV integrase strand transfer inhibitor

BACKGROUND

GSK1265744 is an HIV integrase strand transfer inhibitor selected for clinical development.

OBJECTIVE

This first-time-in-human and phase IIa investigation assessed GSK1265744 antiviral activity, pharmacokinetics, safety, and tolerability in healthy and HIV-1-infected subjects.

METHODS

This double-blind, placebo-controlled study consisted of a dose escalation of single (part A) and multiple (part B) oral doses in 48 healthy subjects and an oral dose (part C) in 11 HIV-1-infected subjects. In part A, 2 cohorts of 9 subjects received either 5 and 25 mg or 10 and 50 mg. In part B, 3 cohorts of 10 subjects received 5, 10, or 25 mg once daily for 14 days. In part C and the phase IIa study, subjects received 5 or 30 mg once daily for 10 days.

RESULTS

Dose-proportional increases in drug exposure were observed in healthy and HIV-1-infected subjects. In healthy subjects, pharmacokinetic variability was low following single or repeat dosing (coefficient of variation, 13%-34% and 15%-23%, respectively). Mean plasma half-life was 31.5 hours. GSK1265744 monotherapy significantly reduced plasma HIV-1 RNA from baseline to day 11 in HIV-1-infected subjects receiving 5 or 30 mg versus placebo (P < .001); mean decrease was 2.2 to 2.3 log10 copies/mL, respectively. Study drug was generally well tolerated with no clinically relevant trends in laboratory values, vital signs, or electrocardiograms.

CONCLUSIONS

GSK1265744 was well tolerated in healthy and HIV-1-infected subjects. Results demonstrate once-daily doses of 5 or 30 mg exceeded minimum target therapeutic concentrations and produced a significant reduction in plasma HIV-1 RNA viral load.

Pharmacodynamic changes with vecuronium in sepsis are associated with expression of α7- and γ-nicotinic acetylcholine receptor in an experimental rat model of neuromyopathy

BACKGROUND

Resistance to non-depolarizing neuromuscular blocking agents induced by sepsis is associated with the qualitative change in the nicotinic acetylcholine receptor (nAChR). This study aims to investigate the effects of sepsis on the neuromuscular block properties of vecuronium in relation to the expression of fetal and neuronal α7 type nAChR.

METHODS

Male Sprague-Dawley rats were randomly divided into sham and sepsis groups. Sepsis was induced by caecal ligation and puncture (CLP). The rats were injected i.v. with ulinastatin or normal saline on Day 10. Neuromuscular block properties of vecuronium were evaluated and neuromuscular function was assessed by electromyography on Days 1, 3, 7, and 14 after CLP. Expression of fetal and neuronal type α7-nAChR on the tibialis anterior muscle was assessed using immunohistochemistry and western blot. The mRNA encoding for γ- and α7 subunits was evaluated by real-time polymerase chain reaction.

RESULTS

The half maximal inhibitory response of vecuronium in the sepsis group significantly increased, peaked on Day 7, and then declined on Day 14 (P<0.05). The neuromuscular function decreased with increasing postoperation time in the sepsis group (P<0.05). Sepsis significantly increased the expression of γ- and α7-nAchR along with expression of γ- and α7 subunits mRNA, peaked on Day 7, and declined on Day 14 (P<0.05). Ulinastatin suppressed the expression of receptor protein and mRNA encoding for γ- and α7 subunits (P<0.05).

CONCLUSIONS

Pharmacodynamic changes with vecuronium seem to be associated with the expression of γ- and α7-nAChR in the skeletal muscle. Ulinastatin can improve this effect by inhibiting the expression of these receptors.

Kallikrein transduced mesenchymal stem cells protect against anti-GBM disease and lupus nephritis by ameliorating inflammation and oxidative stress

Previously we have shown that kallikreins (klks) play a renoprotective role in nephrotoxic serum induced nephritis. In this study, we have used mesenchymal stem cells (MSCs) as vehicles to deliver klks into the injured kidneys and have measured their therapeutic effect on experimental antibody induced nephritis and lupus nephritis. Human KLK-1 (hKLK1) gene was transduced into murine MSCs using a retroviral vector to generate a stable cell line, hKLK1-MSC, expressing high levels of hKLK1. 129/svj mice subjected to anti-GBM induced nephritis were transplanted with 10⁶ hKLK1-MSCs and hKLK1 expression was confirmed in the kidneys. Compared with vector-MSCs injected mice, the hKLK1-MSCs treated mice showed significantly reduced proteinuria, blood urea nitrogen (BUN) and ameliorated renal pathology. Using the same strategy, we treated lupus-prone B6.Sle1.Sle3 bicongenic mice with hKLK1-MSCs and demonstrated that hKLK1-MSCs delivery also attenuated lupus nephritis. Mechanistically, hKLK1-MSCs reduced macrophage and T-lymphocyte infiltration into the kidney by suppressing the expression of inflammation cytokines. Moreover, hKLK1 transduced MSCs were more resistant to oxidative stress-induced apoptosis. These findings advance genetically modified MSCs as potential gene delivery tools for targeting therapeutic agents to the kidneys in order to modulate inflammation and oxidative stress in lupus nephritis.